Composite article

ABSTRACT

A composite article includes a low surface energy polymer layer, a poly(meth)acrylate layer, an epoxide layer, and a hydrolytically resistant layer. The poly(meth)acrylate layer is disposed on and in direct contact with the low surface energy polymer layer and includes the reaction product of at least one acrylate that is polymerized in the presence of an organoborane initiator, such that the poly(meth)acrylate includes boron. The epoxide layer is disposed on and in direct contact with the poly(meth)acrylate layer. The hydrolytically resistant layer is disposed on and in direct contact with the epoxide and is the reaction product of an isocyanate component and an isocyanate-reactive component reacted in the presence of a curing agent. The isocyanate-reactive component includes a polydiene polyol and the curing agent crosslinks the carbon-carbon double bonds of the polydiene polyol.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/279,033, filed Jan. 15, 2016; U.S. Provisional Application No.62/279,027, filed Jan. 15, 2016; U.S. Provisional Application No.62/279,026, filed Jan. 15, 2016; and U.S. Provisional Application No.62/279,029, filed Jan. 15, 2016, the contents of each of which areincorporated herein by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a composite article and amethod of forming the composite article. More particularly, thecomposite article includes a low surface energy polymer, apoly(meth)acrylate, an epoxide, and a hydrolytically resistant layer.The composite article may be used in subsea applications such as for usein subsea pipelines and other subsea structures.

BACKGROUND

Domestic energy needs currently outpace readily accessible energyresources, which has forced an increasing dependence on foreignpetroleum fuels, such as oil and gas. At the same time, existing energyresources are significantly underutilized, in part due to inefficientoil and gas procurement methods.

Petroleum fuels, such as oil and gas, are typically procured fromsubsurface reservoirs via a wellbore that is drilled by a rig. Inoffshore oil and gas exploration endeavors, the subsurface reservoirsare beneath the ocean floor. To access the petroleum fuels, the rigdrills into the ocean floor down to approximately one to two milesbeneath the ocean floor. Various subsea pipelines and structures areutilized to transport the petroleum fuels from this depth beneath theocean floor to above the surface of the ocean and particularly to an oilplatform located on the surface of the ocean. These subsea pipelines andother structures may be made of a metallic material or a combination ofmetallic materials. The petroleum fuels, such as the oil, originating ata depth from about one to two miles beneath the ocean floor, are veryhot (e.g. around 130° C.). In contrast, at this depth, the seawater isvery cold (e.g. around 4° C.). This vast difference in temperaturerequires that the various subsea pipelines and structures be insulatedto maintain the relatively high temperature of the petroleum fuels suchthat the fuels, such as oil and gas, can easily flow through the subseapipelines and other subsea structures. Generally, if the fuel, such asoil, becomes too cold due to the temperature of the seawater, it willbecome too viscous to flow through the pipelines and other structuresand will not be able to reach the ocean surface and/or oil platform.Even in instances where the fuel may be able to flow, the fuel may flowtoo slowly to reach the ocean surface and/or the oil platform in anefficient amount of time for the desired operating conditions.Alternatively and/or additionally, the fuel may form waxes thatdetrimentally act to clog the pipelines and structures. Yet further, dueto the cold temperature of the seawater, the fuel may form hydrates thatdetrimentally change the nature of the fuel and may also act to clog thepipelines and structures.

In other examples, pipelines may be as long as 50 miles and may be bothabove water and below water. While traveling over such distances, thefuel is exposed to many temperature changes. To complicate theseinstances, the fuel must also travel, in the pipelines, 50 miles throughthese temperature changes and from one to two miles beneath the oceanfloor to the oil platform above the ocean surface, without losing itsintegrity. For example, the fuel may need to have a low viscosity toremain flowable during these distances and may need to be adequatelyuniform, e.g., without detrimental hydrates and waxes.

In view of these types of issues, subsea structures are typicallyconstructed by coating a central tube or passageway with insulation.However, during construction, the ends of the structures typically arenon-insulated to allow for welding or other connections to be made toextend the length of the structures. For that reason, the subseastructures must be patched after welding with a polymer to ensurecontinuity of insulation and overall integrity. However, in manyinstances, the adhesion (or peel) strength of the applied patch to thesubstrate is poor, as is the hydrolysis resistance of the resultantpatch. Accordingly, there remains an opportunity for improvement.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a composite article that has a firstlayer including a low surface energy polymer, a poly(meth)acrylate layerdisposed on and in direct contact with said first layer, an epoxidelayer disposed on and in direct contact with said poly(meth)acrylatelayer, and a hydrolytically resistant layer disposed on and in directcontact with said epoxide layer. The poly(meth)acrylate layer includesthe reaction product of at least one (meth)acrylate that is polymerizedin the presence of an organoborane initiator. The hydrolyticallyresistant layer includes a hydrolytically resistant polyurethaneelastomer and is the reaction product of an isocyanate component and anisocyanate-reactive component reacted in the presence of a curing agent.The isocyanate-reactive component includes a polydiene polyol having anaverage hydroxy functionality of no greater than about 3 and a numberaverage molecular weight of from about 1000 to less than about 3000g/mol. The curing agent crosslinks the carbon-carbon double bonds of thepolydiene polyol. The hydrolytically resistant layer has an initialtensile strength as measured in accordance with the DIN 53504 S2standard test method, and wherein said hydrolytically resistant layerretains at least 80% of said initial tensile strength as measured inaccordance with the DIN 53504 S2 standard test method and aftersubmersion in standardized seawater for at least about 24 weeks at 102°C. in accordance with ASTM D665.

The present disclosure also provides for the related subsea structuresincluding the composite articles, as well as the associated method forforming the composite articles.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present disclosure will be readily appreciated,as the same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of a subsea pipe that includes a firstlayer including a low surface energy polymer;

FIG. 2 is a perspective view of a subsea structure that includes oneembodiment of the multilayer coating of this disclosure;

FIG. 3 is a side cross-section of one embodiment of the compositearticle of this disclosure; and

FIG. 4 is a graph comparing the change in tensile strength ofelastomeric polyurethane plaques to the number of weeks of immersion.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure includes a composite article (10). The compositearticle (10) typically includes four layers stacked upon one another, asshown in FIG. 3. In various embodiments, the composite article (10)includes, is, consists of, or consists essentially of, a first layer(14), a poly(meth)acrylate layer (16), an epoxide layer (18), and ahydrolytically resistant layer (20). The first layer (14) includes, is,consists of, or consists essentially of, a polymer that has a lowsurface energy. The first layer (14) may be described as a polymerlayer. The poly(meth)acrylate layer (16) includes, is, consists of, orconsists essentially of, a poly(meth)acrylate. The epoxide layer (18)includes, is, consists of, or consists essentially of, an epoxide. Thehydrolytically resistant layer (20) may be described as a hydrolyticallyresistant polymer layer. The hydrolytically resistant layer (20)includes, is, consists of, or consists essentially of, a hydrolyticallyresistant elastomer. In certain embodiments, the hydrolyticallyresistant layer (20) includes, is, consists of, or consists essentiallyof, a hydrolytically resistant polyurethane elastomer layer. Thepoly(meth)acrylate layer (16), the epoxide layer (18), and thehydrolytically resistant layer (20) may be described as additionallayers, as second, third, or fourth layers, etc. In various embodiments,the first layer (14) is described as a first outermost layer (22). Inother embodiments, the hydrolytically resistant layer (20) is describedas a second (e.g. outermost) layer (24). In still other embodiments, thepoly(meth)acrylate layer (16) and the epoxide layer (18) are eachdescribed as second and/or third layers. Each of these layers isdescribed in greater detail below. The terminology “consist essentiallyof” above describes embodiments that may be free of extraneous polymersor monomers that are reacted to form polymers. Relative to the compositearticle (10) itself, the terminology “consists essentially of” maydescribe embodiments that are free of additional layers, e.g. as wholelayers or as partial layers.

The composite article (10) typically has increased peel strength (i.e.,90° peel strength), e.g. as compared to a composite article (10) that isfree of the (meth)acrylate layer and/or the epoxide layer (18). Invarious embodiments, the composite article (10) has a 90° peel strength(which may be an average or mean peel strength) of at least 55, 60, 65,70, 75, 80, 85, 90, 95, 100, 55 to 100, 60 to 95, 65 to 85, 70 to 80, 75to 80, or 80 to 85, pli (pounds per linear inch, with 1 pound per linearinch corresponding to 1178.57967 grams per linear centimeter) measuredusing ASTM D6862. Typically, these values are reported as an averagepeel strength.

In alternative embodiments, all values and ranges of values between theaforementioned values are hereby expressly contemplated.

Peel strength can be measured between many different layers. Forexample, the aforementioned peel strength may be measured between thehydrolytically resistant layer (20) and the epoxide layer (18).Alternatively, the peel strength may be measured between thehydrolytically resistant layer (20) and the poly(meth)acrylate layer(16) or the hydrolytically resistant layer (20) and the first layer(14). The peel strength is related to the type of failure of thecomposite article (10) when force is applied. For example, when peelstrength is measured, the hydrolytically resistant layer (20) may beginto peel away from another layer, e.g., the epoxide layer (18).Alternatively, when peel strength is measured, the hydrolyticallyresistant layer (20) may break apart/away from the composite article(10) and, for example, the epoxide layer (18). This is typicallydescribed in the art as cohesive failure. Typically, cohesive failure ispreferred.

First Layer (14):

The first layer (14) of the composite article (10) may include, be,consist essentially of, or consist of, a low surface energy polymer. Theterminology “low surface energy” typically describes a polymer that hasa surface energy of less than about 40 mN/m (milli-Newtons per meter),as determined at 20° C. by ASTM D7490-13.

In various embodiments, the low surface energy polymer is chosen frompolyethylene, polypropylene, and combinations thereof. In still otherembodiments, the low surface energy polymer is chosen from those setforth immediately below and combinations thereof.

Surface free energy (SFE) at 20° C. Name CAS Ref -No. in mN/mPolystyrene PS  9003-53-6 40.7 Polyamide-12 PA-12 24937-16-4 40.7Poly-a-methyl styrene PMS  9017-21-4 39 (Polyvinyltoluene PVT)Polyethylacryl ate PEA  9003-32-1 37 Polyvinyl fluoride PVF 24981-14-436.7 Polyvinylacetate PVA  9003-20-7 36.5 Polyethylmethacrylate PEMA 9003-42-3 35.9 Polyethylene-linear PE  9002-88-4 35.7Polyethylene-branched PE  9002-88-4 35.3 Polycarbonate PC 24936-68-334.2 Polyisobutylene PM  9003-27-4 33.6 Polytetramethylene oxide PTME25190-06-1 31.9 (Polytetrahydrofurane PTHF) Polybutylmethacrylate PBMA25608-33-7 31.2 Polychlorotrifluoroethylene PCTrFE 25101-45-5 30.9Polyisobutylmethacrylate PIBMA  9011-15-8 30.9 Poly(t-butylmethacrylate)PtBMA — 30.4 Polyvinylidene fluoride PVDF 24937-79-9 30.3Polypropylene-isotactic PP 25085-53-4 30.1 Polyhexylmethacrylate PHMA25087-17-6 30 Polytrifluoroethylene P3FEt/PTrFE 24980-67-4 23.9Polytetrafluoroethylene PTFE  9002-84-0 20 Polydimethylsiloxane PDMS 9016-00-6 19.8

The first layer (14) may be an outermost layer of the composite article(10) or may be an interior layer of a larger article. If an outermostlayer, the first layer (14) is free of contact with any other layer anexternal side and faces the environment on that side.

The first layer (14) is not limited to any particular dimensions orthickness. In various embodiments, the first layer (14) has a thicknessof from 0.1 inches to 1 foot or more (with 1 inch equal to about 2.54 cmand wherein 1 foot equal to about 30.48 cm). In various embodiments, thethickness is from 0.25 to 6 inches, from 0.25 to 3 inches, from 0.25 to1 inch, from 0.25 to 0.75, or from 0.25 to 0.5, inches (with 1 inchequal to about 2.54 cm). In various non-limiting embodiments, all valuesand ranges of values between the aforementioned values are herebyexpressly contemplated.

Poly(meth)acrylate Layer (16):

The composite article (10) also includes the poly(meth)acrylate layer(16). The poly(meth)acrylate layer (16) is disposed on and in directcontact with the first layer (14). In other words, there is nointermediate layer or tie layer disposed between the poly(meth)acrylatelayer (16) and the first layer (14). The poly(meth)acrylate layer (16)may be include, consist essentially of, or consist of, apoly(meth)acrylate.

The poly(meth)acrylate itself may include, consist essentially of, orconsist of, the reaction product of at least one acrylate that ispolymerized in the presence of an organoborane initiator. Theterminology “consist essentially of” describes an embodiment that isfree of polymer or monomers that are reacted to form polymers. The atleast one acrylate may be a single acrylate, two acrylates, threeacrylates, etc, each of which may independently be an acrylate or amethacrylate (collectively alternatively referred to as (meth)acrylate).The (meth)acrylate may be described as a (meth)acrylate that has 3 to 20carbon atoms, e.g. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, or 20, carbon atoms or any range of values. In otherembodiments, the (meth)acrylate is chosen from hydroxypropylmethacrylate, 2-ethylhexylacrylate, acrylic acid, and combinationsthereof In further embodiments, the (meth)acrylate is chosen from2-ethylhexylacrylate, 2-ethylhexylmethacrylate, methylacrylate,methylmethacrylate, butylacrylate, ethyl acrylate, hexylacrylate,isobutylacrylate, butylmethacrylate, ethylmethacrylate,isooctylacrylate, decylacrylate, dodecylacrylate, vinyl acrylate,acrylic acid, methacrylic acid, neopentylglycol diacrylate,neopentylglycoldimethacrylate, tetrahydrofurfuryl methacrylate,caprolactone acrylate, perfluorobutyl acrylate, perfluorobutylmethacrylate, 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate, 1H, 1H, 2H,2H-heptadecafluorodecyl methacrylate, glycidyl acrylate, glycidylmethacrylate, allyl glycidyl ether, allyl acrylate, allyl methacrylate,stearyl acrylate, stearyl methacrylate, tetrahydrofurfuryl acrylate,2-hydroxyethyl acryl ate, 2-hydroxyethyl methacrylate, diethyleneglycoldiacrylate, diethyleneglycol dimethacrylate, dipropyl eneglycoldiacrylate, dipropyleneglycol dimethacrylate, polyethyleneglycoldiacrylate, polyethyleneglycol dimethacrylate, polypropyleneglycoldiacrylate, tetrahydroperfluoroacrylate, phenoxyethyl acrylate,phenoxyethyl methacrylate, bisphenol A acrylate, bisphenol Adimethacrylate, ethoxylated bisphenol A acrylate, ethoxylated bisphenolA methacrylate, hexafluoro bisphenol A diacrylate, hexafluoro bisphenolA dimethacrylate, N-vinyl pyrrolidone, N-vinyl caprolactam, N-isopropylacrylamide, N,N-dimethylacrylamide, t-octyl acrylamide,cyanotethylacrylates, diacetoneacrylamide, N-vinylacetamide,N-vinylformamide, polypropyleneglycol dimethacrylate,trimethylolpropanetriacrylate, trimethylolpropanetrimethacrylate,ethoxylated trimethylolropanetriacrylate, ethoxylatedtrimethylolpropanetrimethacrylate, pentaerythritol triacrylate,pentaerythritol trimethacrylate, pentaerythritol tetraacrylate,pentaerythritol tetramethacrylate, and combinations thereof. The atleast one (meth)acrylate may include only acrylate or methacrylatefunctionality. Alternatively, the at least one (meth)acrylate mayinclude both acrylate functionality and methacrylate functionality.

In various embodiments, the at least one (meth)acrylate is chosen frommonofunctional acrylates and methacrylate esters and substitutedderivatives thereof such as cyano, chloro, amino and silane derivativesas well as blends of substituted and unsubstituted monofunctionalacrylate and methacrylate esters. In other embodiments, the at least one(meth)acrylate is chosen from lower molecular weight methacrylate estersand amides such as methyl methacrylate, ethyl methacrylate, butylmethacrylate, methoxy ethyl methacrylate, cyclohexyl methacrylate,tetrahydrofurfuryl methacrylate, N,N-dimethyl methacrylamide and blendsthereof. In still other embodiments, the at least one (meth)acrylate ischosen from methyl acrylate, ethyl acrylate, isobornyl methacrylate,butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexylmethacrylate, decylmethacrylate, dodecyl methacrylate, tert-butylmethacrylate, acrylamide, N-methyl acrylamide, diacetone acrylamide,N-tert-butyl acrylamide, N-tert-octyl acrylamide, N-decylmethacrylamide, gamma-methacryloxypropyl trimethoxysilane, 2-cyanoethylacrylate, 3-cyanopropyl acrylate, tetrahydrofurfuryl chloroacrylate,glycidyl acrylate, glycidyl methacrylate, and the like. In furtherembodiments, the at least one (meth)acrylate is chosen from alkylacrylates having 4 to 10 carbon atoms in the alkyl group, such as blendsof methyl methacrylate and butylacrylate. In even further embodiments,the at least one (meth)acrylate is chosen from hexanedioldiacrylate,ethylene glycol dimethacrylate, ethylene glycol diacrylate, triethyleneglycol dimethacrylate, polyethylene glycol diacrylate, tetraethyleneglycol di(meth)acrylate, glycerol diacrylate, diethyleneglycoldimethacrylate, pentaerythritol triacrylate, trimethylolpropanetrimethacrylate, as well as other polyether diacrylates anddimethacrylates.

In further embodiments, the at least one (meth)acrylate has the formula:

wherein R and R′ are each hydrogen or organic radicals, and X is oxygen.Blends of (meth)acrylic monomers may also be used. The at least one(meth)acrylate may be monofunctional, polyfunctional or a combinationthereof.

The at least one (meth)acrylate is polymerized in the presence of anorganoborane initiator to form the poly(meth)acrylate. Thispolymerization typically results in the poly(meth)acrylate includingamounts of boron that remain from the organoborane initiator (e.g., inthe form of oxidized by-products). In other words, the organoboraneinitiator includes boron atoms. After reaction to form thepoly(meth)acrylate, some of the boron atoms may remain in thepoly(meth)acrylate. As just one example, the presence of the boron atomsmay differentiate the poly(meth)acrylate formed in the presence of theorganoborane initiator from other poly(meth)acrylate formed usingdifferent initiation mechanisms or different initiators. In variousembodiments, the amount of boron atoms in the poly(meth)acrylate may befrom 10 to 10,000,000, from 10 to 1,000,000, from 10 to 100,000, from100 to 10,000, from 100 to 5,000, from 500 to 5,000, or from 500 to2,000, parts by weight per one million parts by weight (ppm) of the atleast on (meth)acrylate or of the poly(meth)acrylate. In alternativeembodiments, all values and ranges of values between the aforementionedvalues are hereby expressly contemplated.

The organoborane initiator may be any organoborane compound known in theart capable of generating free radicals. In various embodiments, theorganoborane initiator includes tri-functional boranes which include thegeneral structure:

wherein each of R¹-R³ independently has from 1 to 20 carbon atoms andwherein each of R¹-R³ independently comprise one an aliphatichydrocarbon group and an aromatic hydrocarbon group. The aliphaticand/or aromatic hydrocarbon groups may be linear, branched, and/orcyclic. Suitable examples of the organoborane include, but are notlimited to, tri-methylborane, tri-ethylborane, tri-n-butylborane,tri-n-octylborane, tri-sec-butylborane, tri-dodecylborane,phenyldiethylborane, and combinations thereof. In one embodiment, theorganoborane includes tri-n-butylborane.

The organoborane initiator may be derived from decomplexation of anair-stable complex of an organoborane compound and an organonitrogencompound. In one embodiment, the organoborane initiator is furtherdefined as an organoborane-organonitrogen complex. Suitable organoboraneinitiators include, but are not limited to, organoborane-aminecomplexes, organoborane-azole complexes, organoborane-amidine complexes,organoborane-heterocyclic nitrogen complexes, amido-organoboratecomplexes, and combinations thereof. In one embodiment theorganoborane-amine complex is or includes a trialkylborane-aminecomplex. In one embodiment, the organoborane initiator is furtherdefined as an organoborane-amine complex. A typical organoborane-aminecomplex includes a complex formed between an organoborane and a suitableamine that renders the organoborane-amine complex stable at ambientconditions. Any organoborane-amine complex known in the art may be used.Typically, the organoborane-amine complex is capable of initiatingpolymerization or cross-linking of the radical curable organic compoundthrough introduction of an amine-reactive compound, and/or by heating.That is, the organoborane-amine complex may be destabilized at ambienttemperatures through exposure to suitable amine-reactive compounds. Heatmay be applied if needed or desired. The organoborane-amine complextypically has the formula:

wherein B represents boron. Additionally, each of R⁴, R⁵, and R⁶ istypically independently selected from the group of a hydrogen atom, acycloalkyl group, a linear or branched alkyl group having from 1 to 12carbon atoms in a backbone, an alkylaryl group, an organosilane group,an organosiloxane group, an alkylene group capable of functioning as acovalent bridge to the boron, a divalent organosiloxane group capable offunctioning as a covalent bridge to the boron, and halogen substitutedhomologues thereof, such that at least one of R⁴, R⁵, and R⁶ includesone or more silicon atoms, and is covalently bonded to boron. Further,each of R⁷, R⁸, and R⁹ typically yields an amine compound or a polyaminecompound capable of complexing the boron. Two or more of R⁴, R⁵, and R⁶and two or more of R⁷, R⁸, and R⁹ typically combine to form heterocyclicstructures, provided a sum of the number of atoms from R⁴, R⁵, R⁶, R⁷,R⁸, and R⁹ does not exceed 11.

Additionally, any amine known in the art may be used to form theorganoborane-amine complex. Typically, the amine includes at least oneof an alkyl group, an alkoxy group, an imidazole group, an amidinegroup, an ureido group, and combinations thereof. Particularly suitableamines include, but are not limited to, 1,3 propane diamine,1,6-hexanediamine, methoxypropylamine, pyridine, isophorone diamine, andcombinations thereof

The organoborane initiator may be used in any amount to form thepoly(meth)acrylate. Typically, the organoborane initiator is used in anamount equivalent to of from 0.01 to 95, more typically of from 0.1 to80, even more typically of from 0.1 to 30, still more typically of from1 to 20, and most typically of from 1 to 15 parts by weight per 100parts by weight of the poly(meth)acrylate. The amounts of theorganoborane initiator typically depend upon a molecular weight andfunctionality of the organoborane initiator and the presence of othercomponents such as fillers. The amounts of the organoborane initiatortypically depend upon a molecular weight and functionality of theorganoborane initiator and the presence of other components such asfillers. In various embodiments, the amount used is based on percentboron in the reaction mixture, calculated by the weight of activeingredients/components (e.g. acrylic monomers).

In addition to the organoborane initiator, a reactive compound, such asa decomplexer, may also be utilized or may be omitted (if thedecomplexer is omitted, heat is used to initiate the reaction). Forexample, an organoborane-organonitrogen complex (acting as theorganoborane initiator) may interact with a nitrogen-reactive compoundto initiate polymerization or cross-linking of the at least oneacrylate. This allows the at least one (meth)acrylate to polymerize atlow temperatures and with decreased reaction times. Typically thisoccurs when the nitrogen-reactive compound is mixed with theorganoborane-organonitrogen complex and exposed to an oxygenatedenvironment at temperatures below a dissociation temperature of theorganoborane-organonitrogen complex, including room temperature andbelow. The amine-reactive nitrogen-reactive compound may be or includeany nitrogen-reactive compound known in the art and can be delivered asa gas, liquid, or solid. In one embodiment, the nitrogen-reactivecompound includes free radical polymerizable groups or other functionalgroups such as a hydrolyzable group, and can be monomeric, dimeric,oligomeric or polymeric. In various embodiments, the organoborane-aminecomplex includes a trialkylborane-amine complex. In other embodiments,the amine-reactive compound is chosen from acids, anhydrides, andcombinations thereof.

In various embodiments, the nitrogen-reactive compound is chosen fromthe group of an acid, an anhydride, and combinations thereof. In otherembodiment, the nitrogen-reactive compound includes nitrogen-reactivegroups, such as amine-reactive groups. It is contemplated that thenitrogen-reactive groups may be derived from theorganoborane-organonitrogen complex and/or any additives present. Thenitrogen-reactive compound may be selected from the group of Lewisacids, carboxylic acids, carboxylic acid derivatives, carboxylic acidsalts, isocyanates, aldehydes, epoxides, acid chlorides, sulphonylchlorides, iodonium salts, anhydrides, and combinations thereof In oneembodiment, the amine-reactive compound is selected from the group ofisophorone diisocyanate, hexamethylenediisocyanate, toluenediisocyanate,methyldiphenyldiisocyanate, acrylic acid, methacrylic acid,2-hydroxyethylacrylate, 2-hydroxymethylacrylate,2-hydroxypropylacrylate, 2-hydroxypropylmethacrylate, methacrylicanhydride, undecylenic acid, citraconic anhydride, polyacrylic acid,polymethacrylic acid, and combinations thereof. In yet anotherembodiment, the nitrogen-reactive compound is selected from the group ofoleic acid, undecylenic acid, polymethacrylic acid, stearic acid, citricacid, levulinic acid, and 2-carboxyethyl acrylate, and combinationsthereof. In another embodiment, the nitrogen-reactive compound mayinclude, but is not limited to, acetic acid, acrylic acid, methacrylicacid, methacrylic anhydride, undecylenic acid, oleic acid, an isophoronediisocyanate monomer or oligomer, a hexamethylenediisocyanate monomer,oligomer, or polymer, a toluenediisocyanate monomer, oligomer, orpolymer, a methyldiphenyldiisocyanate monomer, oligomer, or polymer,methacryloylisocyanate, 2-(methacryloyloxy)ethyl acetoacetate,undecylenic aldehyde, dodecyl succinic anhydride, compounds capable ofgenerating nitrogen-reactive groups when exposed to ultravioletradiation such as photoacid generators and iodonium salts including[SbF₆]— counter ions. With such ultraviolet photoacid generators, aphotosensitizing compound such as isopropylthioxanthone may be included.

In various embodiments, the decomplexer includes at least one freeradically polymerizable group and at least one nitrogen-reactive groupin the same molecule. Examples of useful decomplexers include thefollowing: (A)_(a)-Y-(B)_(b) wherein “A” is a group that is capable offorming a covalent bond with an acrylate, “B” is a group that is capableof forming a covalent bond with a nitrogen (e.g. amine) portion of theorganoborane-organonitrogen complex, “Y” is a polyvalent organic linkinggroup; “a” represents the number of free radically polymerizable groups,and “b” represents the number of nitrogen-reactive groups.

Group “A” may include free radically polymerizable groups such as alkenegroups. The alkene group may be unsubstituted or substituted or part ofa cyclic ring structure. Substituted alkenes include, for example, thosealkenes having alkyl aryl group substitution. Typical alkenes are thosehaving terminal unsubstituted double bonds such as allyl groups. Otheralkenes are styryls and acrylics.

Group “B” may include an isocyanate group. Typically, the value of eachof “a” and “b” is at least one. Preferably, the sum of “a” and “b” isless than or equal to six, more preferably less than or equal to four,most preferably two.

Group “Y” may include a variety of different chemical structuresdepending on the reagents used to prepare the decomplexer. Thedecomplexer may include the reaction product of a hydroxyl compoundcontaining a free radically polymerizable group and a polyisocyanate.

The decomplexer/nitrogen-reactive compound may be used in an amountequivalent to of from 0.1 to 95, more typically of from 0.1 to 90, andmost typically of from 1 to 20, parts by weight per 100 parts by weightof the poly(meth)acrylate. The amount of the nitrogen-reactive compoundmay depend upon a molecular weight and functionality of thenitrogen-reactive compound and the presence of other components such asfillers. In another embodiment, the nitrogen-reactive compound istypically used in an amount wherein a molar ratio of nitrogen-reactivegroups to nitrogen groups in the poly(meth)acrylate is of from 0.1 to100, more typically from 0.5 to 50, and most typically from 0.8 to 20.

In various embodiments, the poly(meth)acrylate, the at least one(meth)acrylate, the organoborane initiator, the decomplexer, etc. mayeach be independently as described in U.S. Pat. No. 5,990,036, which isexpressly incorporated herein in its entirety in various non-limitingembodiments.

The poly(meth)acrylate layer (16) is not limited to any particulardimensions or thickness. In various embodiments, the poly(meth)acrylatelayer (16) has a wet film thickness of from 0.025 to 0.5, from 0.050 to0.5, from 0.025 to 0.1, from 0.025 to 0.05, from 0.05 to 0.1, or from0.05 to 0.5, inches (with 1 inch equal to about 2.54 cm). Still further,various embodiments, the poly(meth)acrylate layer (16) has a wet filmthickness of 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085,0.090, 0.095, or 0.100 inches (again with 1 inch equal to about 2.54cm). In various non-limiting embodiments, all values and ranges ofvalues between the aforementioned values are hereby expresslycontemplated. In various non-limiting embodiments, there is no maximumfilm thickness per se. Epoxide layer (18):

Referring now to the epoxide layer (18), the epoxide layer (18) isdisposed on and in direct contact with the poly(meth)acrylate layer(16). In other words, there is no intermediate layer or tie layerdisposed between the poly(meth)acrylate layer (16) and the epoxide layer(18). The epoxide layer (18) may be include, consist essentially of, orconsist of, an epoxide. The epoxide layer (18), and the epoxide itself,are typically formed from an epoxide composition. The epoxide layer (18)may be alternatively described as a “tie layer” or “tie coat”between thehydrolytically resistant layer (20) and the poly(meth)acrylate layer(16). In various embodiments, the epoxide layer (18) is utilized toprevent the hydrolytically resistant layer (20) from contacting thepoly(meth)acrylate layer (16). For example, if a composition that isused to form the hydrolytically resistant layer (20) (that may includean isocyanate and a polyol) were poured onto the poly(meth)acrylatelayer (16), undesirable foaming may occur. Therefore, the epoxide layer(18) can be used to minimize or eliminate this foaming by minimizing oreliminating contact between the hydrolytically resistant layer (20) andthe poly(meth)acrylate layer (16).

The epoxide composition may include an epoxy compound and a hardener.Alternatively, the epoxide composition may be formed from the reactionof an epoxy compound (such as an epoxy resin) and a hardener. The epoxyresin chosen from epoxy resins which are liquid and insoluble in water,and which have low viscosity and little water permeability. In variousembodiments, the epoxy resin is an ordinary glycidyl ether type epoxyresin including bisphenol A type, bisphenol AD type, novolak type,bisphenol F type, and brominated bisphenol A type, special epoxy resinssuch as glycidyl ester type epoxy resins, glycidyl amine type epoxyresins, and heterocyclic epoxy resins, and various modified epoxyresins. In various embodiments, epoxy resins useful herein includeliquids, solids, and mixtures thereof. For example, the epoxy resins canalso be described as polyepoxides such as monomeric polyepoxides (e.g.the diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F,diglycidyl ether of tetrabromobisphenol A, novolac-based epoxy resins,and tris-epoxy resins), higher molecular weight resins (e.g. thediglycidyl ether of bisphenol A advanced with bisphenol A) orpolymerized unsaturated monoepoxides (e.g. glycidyl acrylates, glycidylmethacrylate, allyl glycidyl ether, etc.) to homopolymers or copolymers.In various embodiments, epoxy compounds include, on the average, atleast one pendant or terminal 1,2-epoxy group (i.e., vicinal epoxygroup) per molecule. Solid epoxy resins that may be used can include orbe based on Bisphenol A. For example, a suitable epoxy resin isdiglycidyl ether of bisphenol A Dow Chemical DER 664 UE solid epoxy.

The bisphenol type epoxy resins can be produced via reaction between2,2-bis(4-hydroxyphenyl)propane, i.e., bisphenol A and haloepoxides suchas epichlorohydrin or beta-methylepichlorohydrin. Bisphenol AD typeepoxy resins can be produced via reaction between1,1-bis(4-hydroxyphenyl)ethane, i.e., bisphenol AD and haloepoxides suchas epichlorohydrin or beta-methylepichlorohydrin. Bisphenol F type epoxyresins can be produced through reaction betweenbis(4-hydroxyphenyl)methane i.e. bisphenol F and haloepoxides such asepichlorohydrin or beta-methylepichlorohydrin.

A modifying resin may also be blended with the epoxy resin and chosenfrom a coumarone-indene polymer resin, a dicyclopentadiene polymerresin, an acrylonitrile modified polyvinyl chloride resin, an aminoterminated acrylonitrile-butadiene copolymer resin, and an epoxyterminated polybutadiene resin.

The hardener is typically capable of cross-linking with epoxy groups onthe epoxy resin. Any hardener, e.g., suitable for a 2K epoxy, may beused. Typical hardeners include polymeric amines (polyamines) andpolymeric amides (polyamides) (including, e.g., polyamidoamines), lowmolecular weight amines, and combinations thereof

In various embodiments, an amine is chosen from cycloaliphaticpolyamine, an aliphatic/aromatic polyamine, and an amine adduct. Theamine may be a linear aliphatic polyamine, aromatic polyamine, acidanhydride, imidazole, or an amine chosen from a cycloaliphaticpolyamine, an aliphatic/aromatic polyamine, and an amine adduct. Invarious embodiments, the amine is isophorone diamine and/or m-xylylenediamine. In additional embodiments, the amine adduct is an adduct of apolyamine with an epoxy or similar resin. More particularly, the amineadducts can include polyamines such as m-xylylene diamine and isophoronediamine to which various epoxy resins such as bisphenol A epoxy resinscan be added. The epoxy resins which can form adducts with thepolyamines are as described above.

In various embodiments, the amine includes a polyetheramine-epoxyadduct, that is, a reaction product of a stoichiometric excess of anamine prepolymer with an epoxy resin. The amine may be any amineprepolymer that has at least two amine groups in order to allowcross-linking to take place. The amine prepolymer may include primaryand/or secondary amine groups, and typically includes primary aminegroups. Suitable amine prepolymers include polyether diamines andpolyether triamines, and mixtures thereof. Polyether triamine ispreferred in one embodiment. The polyether amines may be linear,branched, or a mixture. Branched polyether amines are preferred in oneembodiment. Any molecular weight polyetheramine may be used, withmolecular weights in the range of 200-6000 or above being suitable.Molecular weights may be above 1000, or more preferably above 3000.Molecular weights of 3000 or 5000 are preferred in various embodiments.Suitable commercially available polyetheramines include those sold byHuntsman under the Jeffamine trade name. Suitable polyether diaminesinclude Jeffamines in the D, ED, and DR series. These include JeffamineD-230, D-400, D-2000, D-4000, HK-511, ED-600, ED-900, ED-2003, EDR-148,and EDR-176. Suitable polyether triamines include Jeffamines in the Tseries. These include Jeffamine T-403, T-3000, and T-5000. Polyethertriamines are preferred in various embodiments, and a polyether triamineof molecular weight about 5000 (e.g., Jeffamine T-5000) is mostpreferred in another embodiment. The equivalents of any of the above mayalso be used in partial or total replacement.

In further embodiments, the epoxy composition includes 5 to 30 parts byweight of the epoxy compound, 0 to 35 parts by weight of the modifyingresin, and a balance of the amine curing agent, per 100 parts by weightof the composition.

The epoxide composition may also include one or more curing accelerators(catalysts). The curing accelerator typically functions by catalyzingreaction of the epoxy resin and the amine (or hardener). The curingaccelerator may include a tertiary amine, such as2,4,6-tris(dimethylamino-methyl) phenol, available from Air Productsunder the name Ancamine K54. Other amines are described in U.S. Pat. No.4,659,779 which is expressly incorporated herein by reference in itsentirety in various non-limiting embodiments.

In various embodiments, the reaction of the epoxy resin and the amine isas follows:

wherein n is from 5 to 75.

The epoxide layer (18) is not limited to any particular dimensions orthickness. In various embodiments, the epoxide layer (18) has a wet filmthickness of from 0.010 to 0.5, from 0.025 to 0.5, from 0.050 to 0.5,from 0.025 to 0.1, from 0.025 to 0.05, from 0.05 to 0.1, or from 0.05 to0.5, inches (with 1 inch equal to about 2.54 cm). In variousnon-limiting embodiments, all values and ranges of values between theaforementioned values are hereby expressly contemplated.

Hydrolytically Resistant Layer (20):

The hydrolytically resistant layer (20) is disposed on and in directcontact with the epoxide layer (18). In other words, there is nointermediate layer or tie layer disposed between the hydrolyticallyresistant layer (20) and the epoxide layer (18). The hydrolyticallyresistant layer (20) may be include, consist essentially of, or consistof, a hydrolytically resistant elastomer. The hydrolytically resistantelastomer may be a polyurethane elastomer. The polyurethane elastomermay be formed from a polyurethane elastomer composition. Thiscomposition may include the reaction product of an isocyanate componentand an isocyanate-reactive component.

A hydrolytically resistant material, as defined herein, such as thehydrolytically resistant elastomer, is a material (or elastomer) that isresistant to degradation in water.

The isocyanate component may be, include, consist essentially of, orconsist of, any isocyanate known in the art, e.g., aliphaticisocyanates, aromatic isocyanates, polymeric isocyanates, orcombinations thereof. The isocyanate component may be, include, consistessentially of, or consist of, more than one different isocyanate, e.g.,polymeric diphenylmethane diisocyanate and 4,4′-diphenylmethanediisocyanate. In various embodiments, the isocyanate is chosen frondiphenylmethane diisocyanates (MDIs), polymeric diphenylmethanediisocyanates (pMDIs), toluene diisocyanates (TDIs), hexamethylenediisocyanates (HDIs), isophorone diisocyanates (IPDIs), and combinationsthereof.

In various embodiments, the isocyanate component typically includes, butis not limited to, isocyanates, diisocyanates, polyisocyanates, andcombinations thereof. In one embodiment, the isocyanate componentincludes an n-functional isocyanate. In this embodiment, n is a numbertypically from 2 to 5, more typically from 2 to 4, still more typicallyof from 2 to 3, and most typically about 2. It is to be understood thatn may be an integer or may have intermediate values from 2 to 5. Theisocyanate component typically includes an isocyanate selected from thegroup of aromatic isocyanates, aliphatic isocyanates, and combinationsthereof In another embodiment, the isocyanate component includes analiphatic isocyanate such as hexamethylene diisocyanate (HDI),dicyclohexyl-methyl-diisocyanate (H12MDI), isophorone-diisocyanate, andcombinations thereof. If the isocyanate component includes an aliphaticisocyanate, the isocyanate component may also include a modifiedmultivalent aliphatic isocyanate, i.e., a product which is obtainedthrough chemical reactions of aliphatic diisocyanates and/or aliphaticpolyisocyanates. Examples include, but are not limited to, ureas,biurets, allophanates, carbodiimides, uretonimines, isocyanurates,urethane groups, dimers, trimers, and combinations thereof. Theisocyanate component may also include, but is not limited to, modifieddiisocyanates employed individually or in reaction products withpolyoxyalkyleneglycols, diethylene glycols, dipropylene glycols,polyoxyethylene glycols, polyoxypropylene glycols,polyoxypropylenepolyoxethylene glycols, polyesterols, polycaprolactones,and combinations thereof

Alternatively, the isocyanate component can include an aromaticisocyanate. If the isocyanate component includes an aromatic isocyanate,the aromatic isocyanate typically corresponds to the formula R′(NCO)_(z)wherein R′ is aromatic and z is an integer that corresponds to thevalence of R′. Typically, z is at least two. Suitable examples ofaromatic isocyanates include, but are not limited to,tetramethylxylylene diisocyanate (TMXDI), 1,4-diisocyanatobenzene,1,3-diisocyanato-o-xylene, 1,3-diisocyanato-p-xylene,1,3-diisocyanato-m-xylene, 2,4-diisocyanato-1-chlorobenzene,2,4-diisocyanato-1-nitro-benzene, 2,5-diisocyanato-1-nitrobenzene,m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4- and 2,6-toluenediisocyanate, 1,5-naphthalene diisocyanate, 1-methoxy-2,4-phenylenediisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethanediisocyanate, 4,4′-biphenylene diisocyanate,3,3′-dimethyl-4,4′-diphenylmethane diisocyanate,3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, triisocyanates such as4,4′,4″-triphenylmethane triisocyanate polymethylene polyphenylenepolyisocyanate and 2,4,6-toluene triisocyanate, tetraisocyanates such as4,4′-dimethyl-2,2′-5,5′-diphenylmethane tetraisocyanate, toluenediisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethanediisocyanate, 4,4′-diphenylmethane diisocyanate, polymethylenepolyphenylene polyisocyanate, corresponding isomeric mixtures thereof,and combinations thereof. Alternatively, the aromatic isocyanate mayinclude a triisocyanate product of m-TMXDI and 1,1,1-trimethylolpropane,a reaction product of toluene diisocyanate and 1,1,1-trimethyolpropane,and combinations thereof. In one embodiment, the isocyanate componentincludes a diisocyanate selected from the group of methylene diphenyldiisocyanates, toluene diisocyanates, hexamethylene diisocyanates,H12MDIs, and combinations thereof.

The isocyanate component may be an isocyanate pre-polymer. Theisocyanate pre-polymer may be a reaction product of an isocyanate and apolyol and/or a polyamine. The isocyanate used in the pre-polymer can beany isocyanate as described above.

The polyol used to form the pre-polymer may be one or more polyolsdescribed herein typically having a number average molecular weight (Mn)of 400 g/mol or greater, with (Mn) measured by conventional techniquessuch as GPC. Suitable polyols for use in the pre-polymer are typicallyselected from the group of conventional polyols, such as polyetherpolyols, polyester polyols, polyether/ester polyols, and combinationsthereof.

The one or more polyols may each independently be polyether polyols,polyester polyols, polyether/ester polyols, and combinations thereof.The one or more polyols may each independently have a number averagemolecular weight of from about 400 to about 15,000, alternatively fromabout 450 to about 7,000, and alternatively from about 600 to about5,000, g/mol. In another embodiment, each of the one or more polyolsindependently has a hydroxyl number of from about 20 to about 1000,alternatively from about 30 to about 800, alternatively from about 40 toabout 600, alternatively from about 50 to about 500, alternatively fromabout 55 to about 450, alternatively from about 60 to about 400,alternatively from about 65 to about 300, mg KOH/g.

In various embodiments, the polyol is chosen from conventional polyols,including, but not limited to, biopolyols, such as soybean oil,castor-oil, soy-protein, rapeseed oil, etc., derivatives thereof, andcombinations thereof. Suitable polyether polyols include, but are notlimited to, products obtained by the polymerization of a cyclic oxide,for example ethylene oxide (EO), propylene oxide (PO), butylene oxide(BO), or tetrahydrofuran in the presence of polyfunctional initiators.Suitable initiator compounds contain a plurality of active hydrogenatoms, and include water, butanediol, ethylene glycol, propylene glycol(PG), diethylene glycol, triethylene glycol, dipropylene glycol,ethanolamine, diethanolamine, triethanolamine, toluene diamine, diethyltoluene diamine, phenyl diamine, diphenylmethane diamine, ethylenediamine, cyclohexane diamine, cyclohexane dimethanol, resorcinol,bisphenol A, glycerol, trimethylolpropane, 1,2,6-hexanetriol,pentaerythritol, and combinations thereof.

Other suitable polyether polyol copolymers include polyether diols andtriols, such as polyoxypropylene diols and triols andpoly(oxyethylene-oxypropylene)diols and triols obtained by thesimultaneous or sequential addition of ethylene and propylene oxides todi- or trifunctional initiators. Copolymers having oxyethylene contentsof from about 5 to about 90% by weight, based on the weight of thepolyol component, of which the polyols may be block copolymers,random/block copolymers or random copolymers, can also be used. Yetother suitable polyether polyols include polytetramethylene glycolsobtained by the polymerization of tetrahydrofuran.

Suitable polyester polyols include, but are not limited to, aromaticpolyester polyols, hydroxyl-terminated reaction products of polyhydricalcohols, such as ethylene glycol, propylene glycol, diethylene glycol,1,4-butanediol, neopentylglycol, 1,6-hexanediol, cyclohexane dimethanol,glycerol, trimethylolpropane, pentaerythritol or polyether polyols ormixtures of such polyhydric alcohols, and polycarboxylic acids,especially dicarboxylic acids or their ester-forming derivatives, forexample succinic, glutaric and adipic acids or their dimethyl esterssebacic acid, phthalic anhydride, tetrachlorophthalic anhydride ordimethyl terephthalate or mixtures thereof. Polyester polyols obtainedby the polymerization of lactones, e.g. caprolactone, in conjunctionwith a polyol, or of hydroxy carboxylic acids, e.g. hydroxy caproicacid, may also be used.

Suitable polyesteramides polyols may be obtained by the inclusion ofaminoalcohols such as ethanolamine in polyesterification mixtures.Suitable polythioether polyols include products obtained by condensingthiodiglycol either alone or with other glycols, alkylene oxides,dicarboxylic acids, formaldehyde, aminoalcohols or aminocarboxylicacids. Suitable polycarbonate polyols include products obtained byreacting diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol,diethylene glycol or tetraethylene glycol with diaryl carbonates, e.g.diphenyl carbonate, or with phosgene. Suitable polyacetal polyolsinclude those prepared by reacting glycols such as diethylene glycol,triethylene glycol or hexanediol with formaldehyde. Other suitablepolyacetal polyols may also be prepared by polymerizing cyclic acetals.Suitable polyolefin polyols include hydroxy-terminated butadiene homo-and copolymers and suitable polysiloxane polyols includepolydimethylsiloxane diols and triols.

Specific isocyanates that may be included in the isocyanate componentfor preparing the isocyanate prepolymer include, but are not limited to,toluene diisocyanate; 4,4′-diphenylmethane diisocyanate; m-phenylenediisocyanate; 1,5-naphthalene diisocyanate; 4-chloro-1; 3-phenylenediisocyanate; tetramethylene diisocyanate; hexamethylene diisocyanate;1,4-dicyclohexyl diisocyanate; 1,4-cyclohexyldiisocyanate,2,4,6-toluylene triisocyanate,1,3-diisopropylphenylene-2,4-dissocyanate;1-methyl-3,5-diethylphenylene-2,4-diisocyanate;1,3,5-triethylphenylene-2,4-diisocyanate;1,3,5-triisoproply-phenylene-2,4-diisocyanate;3,3′-diethyl-bisphenyl-4,4′-diisocyanate;3,5,3′,5′-tetraethyl-diphenylmethane-4,4′-diisocyanate;3,5,3′,5′-tetraisopropyldiphenylmethane-4,4′-diisocyanate; 1-ethyl-4-ethoxy-phenyl-2,5-diisocyanate; 1,3,5-triethylbenzene-2,4,6-triisocyanate; 1-ethyl-3,5-diisopropylbenzene-2,4,6-triisocyanate and 1,3,5-triisopropylbenzene-2,4,6-triisocyanate. Other suitable polyurethane elastomercompositions can also be prepared from aromatic diisocyanates orisocyanates having one or two aryl, alkyl, arakyl or alkoxy substituentswherein at least one of these substituents has at least two carbonatoms.

The isocyanate component typically has an NCO content of from 3 to 50,alternatively from 3 to 33, alternatively from 18 to 30, weight percentwhen tested in accordance with DIN EN ISO 11909, and a viscosity at 25°C. of from 5 to 2000, alternatively from 100 to 1000, alternatively from150 to 250, alternatively from 180 to 220, mPa·sec when tested inaccordance with DIN EN ISO 3219.

In various embodiments the isocyanate component is, includes, consistsessentially of, or consists of, monomeric and polymeric isocyanate. Forexample, in one embodiment the isocyanate component includes polymericdiphenylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate, andhas an NCO content of about 30 to 33.5 weight percent. Alternatively, inanother embodiment, the isocyanate component includes polymericdiphenylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate, andhas an NCO content of about 31.3 weight percent.

The isocyanate component is typically reacted to form the hydrolyticallyresistant polyurethane elastomer composition in an amount of from 10 to90, alternatively from 20 to 75, alternatively from 30 to 60, percent byweight based on the total weight of all components used to form thepolyurethane elastomer composition. The amount of the aliphaticisocyanate component reacted to form the hydrolytically resistantpolyurethane elastomer composition may vary outside of the ranges above,but is typically both whole and fractional values within these ranges.Further, it is to be appreciated that more than one isocyanate may beincluded in the isocyanate component, in which case the total amount ofall isocyanates included is within the above ranges.

Referring now to the isocyanate-reactive component, this component maybe, include, consist essentially of, or consist of, a polydiene polyol.

The polydiene polyol comprises polymerized diene units. For purposes ofthe subject invention, the term “diene units” is used to describe unitswithin a polymer which were formed from a diene or diolefin, i.e., ahydrocarbon having two carbon-carbon double bonds. Examples of dieneswhich can be used to from the polydiene include, but are not limited to,1,2-propadiene, isoprene, and 1,3-butadiene.

In one embodiment, the polydiene polyol is a polybutadiene polyol, i.e.,is formed from 1,3-butadiene and thus comprises butadiene units. Ofcourse, 1,3-butadiene can polymerize to form 1,4-cis units, 1,4-transunits, and 1,2-vinyl units. The polybutadiene polyol may include, noless than 10, alternatively no less than 15, alternatively no less than20, alternatively no less than 25, alternatively no less than 30,alternatively no less than 35, alternatively no less than 40,alternatively no less than 45, alternatively no less than 50,alternatively no less than 55, alternatively no less than 60,alternatively no less than 65, percent by weight 1,2-vinyl units basedthe total weight of the polybutadiene polyol. It is believed that thestructure of the polybutadiene polyol imparts hydrolytic stability tothe hydrolytically resistant layer (20). It is also believed that thestructure of the polybutadiene polyol imparts hydrophobicity to thehydrolytically resistant layer (20).

The polydiene polyol typically has an average hydroxy functionality nogreater than about 3, alternatively from about 2 to about 3,alternatively about 2. The polybutadiene polyol may include an averagehydroxy functionality of no greater than 3, alternatively no greaterthan 2.7, alternatively no greater than 2.6, alternatively no greaterthan 2.5, alternatively greater than 2.4, alternatively no greater than2.3, alternatively no greater than 2.1, alternatively no greater than2.0. In one embodiment, the polydiene polyol is terminated with hydroxylgroups. In another embodiment, the polydiene polyol is terminated atboth ends with hydroxyl groups. In another embodiment, the polydienepolyol is a hydroxy-terminated polybutadiene, i.e., is a linearpolybutadiene having two primary hydroxy functional groups. In anotherembodiment, the hydroxy-terminated polybutadiene is terminated at eachend with a hydroxy functional group.

The polydiene polyol typically has a number average molecular weight offrom about 1000 to less than about 3000, alternatively from about 1000to less than about 2200, alternatively from 1100 to 2000, alternativelyfrom 1200 to 1800, alternatively from 1300 to 1700, alternatively from1400 to 1600, g/mol, and a viscosity at 30° C. of from 0.5 to 6.0,alternatively from 0.5 to 2.5, alternatively from 0.7 to 2.3,alternatively from 0.8 to 2.1, alternatively from 0.9 to 1.9, Pa·secwhen tested in accordance with DIN EN ISO 3219, as modified for aviscosity measurement at 30° C.

Suitable polydiene polyols are commercially available from TOTAL ofHouston, Tex. under the trade names Poly bd® or Krasol®.

In an exemplary embodiment, the polydiene polyol is a hydroxy-terminatedpolybutadiene having about 20 percent by weight 1,2-vinyl units, amolecular weight of about 1200 to 1350 g/mol, and a viscosity at 30° C.of about 0.9 to 1.9 Pa·sec. In another exemplary embodiment, thepolydiene polyol is a hydroxy-terminated polybutadiene having about 20percent by weight 1,2-vinyl units, a molecular weight of about 1200g/mol, and a viscosity at 30° C. of about 1.4 Pa·sec. In still anotherexemplary embodiment, the polydiene polyol is a hydroxy-terminatedpolybutadiene having about 20 percent by weight 1,2-vinyl units, amolecular weight of about 1350 g/mol, and a viscosity at 30° C. of about1.4 Pa·sec. It is believed that because of the concentration of1,2-vinyl units, i.e., olefinic double bonds, and low molecular weight,the hydroxy-terminated polybutadiene of this embodiment is a liquid atroom temperature. The liquid is typically clear and water-white. Theliquid form facilitates the formation of a consistent and uniformpolyurethane elastomeric composition coating on the subsea structures.Further, the polybutadiene polyol imparts hydrolytic stability, lowmoisture permeability and/or low temperature flexibility to thepolyurethane elastomeric composition. Alternatively, a polydiene polyolthat is a hydroxy-terminated polybutadiene having about 20 percent byweight 1,2-vinyl units, a molecular weight of about 2800 g/mol, and aviscosity at 30° C. of about 5 Pa·sec may be used.

The polydiene polyol is typically present in the isocyanate-reactivecomponent in an amount of from greater than 0 and less than 95 parts byweight based on 100 parts by weight of said isocyanate-reactivecomponent, alternatively from 10 to 95, alternatively from 30 to 90,alternatively from 50 to 90, alternatively from 60 to 90, alternativelyfrom 60 to 80, parts by weight based on 100 parts by weight of theisocyanate-reactive component. The amount of polydiene polyol may varyoutside of the ranges above, but may be both whole and fractional valueswithin these ranges. Further, it is to be appreciated that more than onepolydiene polyol may be included in the isocyanate-reactive component,in which case the total amount of all polydiene polyol included iswithin the above ranges.

In addition to the polydiene polyol, the isocyanate-reactive componentmay also include one or more supplemental polyols. If included, thesupplemental polyol is typically selected from the group of conventionalpolyols which are not polydiene polyols, such as polyether polyols,polyester polyols, polyether/ester polyols, and combinations thereof Inone embodiment, the supplemental polyol has a water content below 0.05percent by weight based on the total weight of the polyol. In additionalembodiments, the supplemental polyol has a total sodium (Na) andpotassium (K) contents less than about 15, alternatively less than about10, alternatively less than about 5 ppm. In one embodiment, theisocyanate-reactive component may also comprise a polyether polyolhaving a higher average hydroxy functionality, e.g., greater than about3. In another embodiment, the polyether polyol and the polydiene polyoltogether have an average hydroxy functionality of no greater than about3, alternatively from about 2 to about 3, alternatively about 2. Thepolyether polyol and polybutadiene polyol together may include anaverage hydroxy functionality of no greater than 3, alternatively nogreater than 2.7, alternatively no greater than 2.6, alternatively nogreater than 2.5, alternatively greater than 2.4, alternatively nogreater than 2.3, alternatively no greater than 2.1, alternatively nogreater than 1.9, alternatively no greater than 1.7.

Suitable polyether polyols for use as the supplemental polyol include,but are not limited to, products obtained by the polymerization of acyclic oxide, for example ethylene oxide (EO), propylene oxide (PO),butylene oxide (BO), or tetrahydrofuran in the presence ofpolyfunctional initiators. Suitable initiator compounds contain aplurality of active hydrogen atoms, and include water, butanediol,ethylene glycol, propylene glycol (PG), diethylene glycol, triethyleneglycol, dipropylene glycol, ethanolamine, diethanolamine,triethanolamine, toluene diamine, diethyl toluene diamine, phenyldiamine, diphenylmethane diamine, ethylene diamine, cyclohexane diamine,cyclohexane dimethanol, resorcinol, bisphenol A, glycerol,trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, and combinationsthereof.

Other suitable polyether polyols for use as the supplemental polyol arepolyether polyol copolymers that include polyether diols and triols,such as polyoxypropylene diols and triols andpoly(oxyethylene-oxypropylene)diols and triols obtained by thesimultaneous or sequential addition of ethylene and propylene oxides todi- or trifunctional initiators. Copolymers having oxyethylene contentsof from about 5 to about 90% by weight, based on the weight of thepolyol component, of which the polyols may be block copolymers,random/block copolymers or random copolymers, can also be used. Yetother suitable polyether polyols include polytetramethylene glycolsobtained by the polymerization of tetrahydrofuran.

Suitable polyester polyols for use as the supplemental polyol include,but are not limited to, aromatic polyester polyols, hydroxyl-terminatedreaction products of polyhydric alcohols, such as ethylene glycol,propylene glycol, diethylene glycol, 1,4-butanediol, neopentylglycol,1,6-hexanediol, cyclohexane dimethanol, glycerol, trimethylolpropane,pentaerythritol or polyether polyols or mixtures of such polyhydricalcohols, and polycarboxylic acids, especially dicarboxylic acids ortheir ester-forming derivatives, for example succinic, glutaric andadipic acids or their dimethyl esters sebacic acid, phthalic anhydride,tetrachlorophthalic anhydride or dimethyl terephthalate or mixturesthereof. Polyester polyols obtained by the polymerization of lactones,e.g. caprolactone, in conjunction with a polyol, or of hydroxycarboxylic acids, e.g. hydroxy caproic acid, may also be used.

Suitable polyesteramides polyols for use as the supplemental polyol maybe obtained by the inclusion of aminoalcohols such as ethanolamine inpolyesterification mixtures. Suitable polythioether polyols for use asthe supplemental polyol include products obtained by condensingthiodiglycol either alone or with other glycols, alkylene oxides,dicarboxylic acids, formaldehyde, aminoalcohols or aminocarboxylicacids. Suitable polycarbonate polyols for use as the supplemental polyolinclude products obtained by reacting diols such as 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, diethylene glycol or tetraethyleneglycol with diaryl carbonates, e.g. diphenyl carbonate, or withphosgene. Suitable polyacetal polyols for use as the supplemental polyolinclude those prepared by reacting glycols such as diethylene glycol,triethylene glycol or hexanediol with formaldehyde. Other suitablepolyacetal polyols for use as the supplemental polyol may also beprepared by polymerizing cyclic acetals. Suitable polyolefin polyols foruse as the supplemental polyol include hydroxy-terminated butadienehomo- and copolymers and suitable polysiloxane polyols includepolydimethylsiloxane diols and triols.

Other suitable supplemental polyols include, but are not limited to,biopolyols, such as soybean oil, castor-oil, soy-protein, rapeseed oil,etc., and derivatives and combinations thereof.

In addition, lower molecular weight hydroxyl-functional compounds mayalso be utilized such as ethylene glycol, diethylene glycol, propyleneglycol, dipropylene glycol, butane diol, glycerol, trimethylpropane,triethanolamine, pentaerythritol, sorbitol, and combinations thereof Thesupplemental polyol may be included in the isocyanate-reactive componentin an amount of from 1 to 70, alternatively from 5 to 50, alternatively5 to 25, percent by weight based on the total weight of all componentsincluded in the isocyanate-reactive component. The amount ofsupplemental polyol may vary outside of the ranges above, but may beboth whole and fractional values within these ranges. Further, it is tobe appreciated that more than one supplemental polyol may be included inthe isocyanate-reactive component, in which case the total amount of allsupplemental polyol included is within the above ranges. Particularlysuitable supplemental polyols are commercially available from BASFCorporation of Wyandotte, Mich., under the trade name of Pluracol®. In apreferred embodiment, the supplemental polyol is a polyether polyolavailable from BASF Corporation of Wyandotte, Mich. under the trade namePluracol® 2010.

In another embodiment, the supplemental polyol has a number averagemolecular weight of from about 400 to about 15,000, alternatively fromabout 450 to about 7,000, and alternatively from about 600 to about5,000, g/mol. In another embodiment, the supplemental polyol has ahydroxyl number of from about 20 to about 1000, alternatively from about30 to about 800, alternatively from about 40 to about 600, alternativelyfrom about 50 to about 500, alternatively from about 55 to about 450,alternatively from about 60 to about 400, alternatively from about 65 toabout 300, mg KOH/g. In yet another embodiment, the supplemental polyolhas a nominal hydroxy functionality of from about 2 to about 4,alternatively from about 2.2 to about 3.7, and alternatively of fromabout 2.5 to about 3.5.

In addition to the polydiene polyol, the isocyanate-reactive componentmay also include one or more chain extenders and/or crosslinkers(hereinafter collectively referred to as chain extenders. The chainextender has at least two hydroxyl functional groups and a numberaverage molecular weight of no more than 400 g/mol. Specifically, thechain extender typically has a nominal functionality no greater than 4,alternatively no greater than 3, alternatively no greater than 2.5,alternatively from 1.9 to 3.1, alternatively from 1.9 to 2.5, and anumber average molecular weight of from 50 to 400, alternatively from 60to 300, alternatively from 62 to 220, alternatively from 70 to 220,alternatively from 75 to 195, alternatively about 192, alternativelyabout 134, alternatively about 76.

Non-limiting examples of such chain extenders include, but are notlimited to, straight chain glycols having from 2 to 20 carbon atoms inthe main chain, diols having an aromatic ring and having up to 20 carbonatoms, and even triols such as those set forth below. Examples ofsuitable chain extenders, for purposes of the present invention, includepropylene glycol, dipropylene glycol, tripropylene glycol, di ethyleneglycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,1,6-hexanediol, 2-butene-1,4-diol, thoidiethanol, butyleneglycol,1,4-bis(hydroxyethoxy)benzene, p-xylene glycol and hydrogenated productsthereof, trimethylol, stearyl alcohol, N,N-diisopropanol aniline,2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol,2,2,4-trimethyl-1,3-pentanediol, and hydroxyethyl acrylate. In oneembodiment, the chain extender may comprise an alkylene glycol. In onespecific embodiment, the alkylene glycol is selected from the group ofpropylene glycol, dipropylene glycol, tripropylene glycol, andcombinations thereof In another embodiment, the chain extender isdipropylene glycol. It is believed that the chain extender imparts aneven increased hydrolytic resistance, as well as increased strength,tear strength, and hardness to the polyurethane elastomeric compositionas a result of its lower molecular weight and its molecular structure,e.g., ether groups.

In one embodiment, the isocyanate-reactive component consistsessentially of the chain extender comprising the polydiene polyol and analkylene glycol. In this and additional embodiments, the chain extendermay present in the isocyanate-reactive component in an amount of morethan about 5, alternatively more than about 10, alternatively more thanabout 15, alternatively more than about 20 parts by weight based on 100parts by weight of all the components included in theisocyanate-reactive component. In other embodiments, the chain extendermay present in the isocyanate-reactive component in an amount of lessthan about 30, alternatively less than about 25, alternatively less thanabout 20, parts by weight based on 100 parts by weight of all thecomponents included in the isocyanate-reactive component. In anotherembodiment, the isocyanate-reactive component consists essentially ofthe chain extender comprising an alkylene glycol, the polydiene polyol,and a polyether supplemental polyol. The amount of chain extender mayvary outside of the ranges above, but may be both whole and fractionalvalues within these ranges. Further, it is to be appreciated that morethan one chain extender may be included in the isocyanate-reactivecomponent, in which case the total amount of all chain extender includedis within the above ranges.

In addition to the polydiene polyol, the isocyanate-reactive componentmay also include one or more amines. Any amine known in the art may beutilized. For example, the amine may be chosen from MDA, TDA, ethylene-,propylene- butylene-, pentane-, hexane-, octane-, decane-, dodecane-,tetradecane-, hexadecane-, octadecanediamines, Jeffamines-200, -400,-2000, -5000, hindered secondary amines like Unilink 4200, Curene 442,Polacure 740, Ethacure 300, Lonzacure M-CDEA, Polyaspartics, 4,9Dioxadodecan-1,12-diamine, and combinations thereof In otherembodiments, the amine is chosen from Lupragen®API-N-(3-Aminopropyl)imidazole, Lupragen® DMI-1,2-Dimethylimidazole,Lupragen® DMI-1,2-Dimethylimidazole, Lupragen® N100-N,N-Dimethylcyclohexylamine, Lupragen® N 101-Dimethylethanolamine,Lupragen® N 103-N,N-Dimethylbenzylamine, Lupragen® N104-N-Ethylmorpholine, Lupragen® N 105-N-Methylmorpholine, Lupragen® N106-2,2′-Dimorpholinodiethylether, Lupragen® N107-Dimethylaminoethoxyethanol, Lupragen® N 201-TEDA in DPG, Lupragen® N202-TEDA in BDO, Lupragen® N 203-TEDA in MEG, Lupragen® N204-N,N′-Dimethylpiperazine, Lupragen® N205-Bis(2-dimethylaminoethyl)ether, Lupragen® N206-Bis(2-dimethylaminoethyl)ether, Lupragen® N301-Pentamethyldiethylenetriamine, Lupragen® N 301-Pentamethyldiethylenetriamine, Lupragen® N400-Trimethylaminoethylethanolamine, Lupragen® N500-Tetramethyl-1,6-hexandiamine, Lupragen® N500-Tetramethyl-1,6-hexanediamine, Lupragen® N 600-S-Triazine, Lupragen®N 700-1,8-Diazabicyclo-5,4,0-undecene-7, Lupragen®NMI-N-Methylimidazole, and combinations thereof

The isocyanate-reactive component may also include one or morecatalysts. The catalyst is typically present in the isocyanate-reactivecomponent to catalyze the reaction between the isocyanate component andthe isocyanate-reactive component. That is, isocyanate-reactivecomponent typically includes a “polyurethane catalyst” which catalyzesthe reaction between an isocyanate and a hydroxy functional group of theisocyanate reactive group, including a hydroxy group from the polydienepolyol. It is to be appreciated that the catalyst is typically notconsumed in the exothermic reaction between the isocyanate and thepolyol. More specifically, the catalyst typically participates in, butis not consumed in, the exothermic reaction. The catalyst may includeany suitable catalyst or mixtures of catalysts known in the art.Examples of suitable catalysts include, but are not limited to, gelationcatalysts, e.g., amine catalysts in dipropylene glycol; blowingcatalysts, e.g., bis(dimethylaminoethyl)ether in dipropylene glycol; andmetal catalysts, e.g., organo-tin compounds, organo-bismuth compounds,organo-lead compounds, etc.

This catalyst may be any in the art. In one embodiment, the isocyanatecatalyst is an amine catalyst. In another embodiment, the isocyanatecatalyst is an organometallic catalyst.

The isocyanate catalyst may be or include a tin catalyst. Suitable tincatalysts include, but are not limited to, tin(II) salts of organiccarboxylic acids, e.g. tin(II) acetate, tin(II) octoate, tin(II)ethylhexanoate and tin(II) laurate. In one embodiment, the isocyanatecatalyst is or includes dibutyltin dilaurate, which is a dialkyltin(IV)salt of an organic carboxylic acid. Specific examples of non-limitingisocyanate catalysts are commercially available from Air Products andChemicals, Inc. of Allentown, Pa., under the trademark DABCO®. Theisocyanate catalyst can also include other dialkyltin(IV) salts oforganic carboxylic acids, such as dibutyltin diacetate, dibutyltinmaleate and dioctyltin diacetate.

Examples of other suitable but non-limiting isocyanate catalysts includeiron(II) chloride; zinc chloride; lead octoate;tris(dialkylaminoalkyl)-s-hexahydrotriazines includingtris(N,N-dimethylaminopropyl)-s-hexahydrotriazine; tetraalkylammoniumhydroxides including tetramethylammonium hydroxide; alkali metalhydroxides including sodium hydroxide and potassium hydroxide; alkalimetal alkoxides including sodium methoxide and potassium isopropoxide;and alkali metal salts of long-chain fatty acids having from 10 to 20carbon atoms and/or lateral OH groups.

Further examples of other suitable but non-limiting isocyanate catalystsinclude N,N,N-dimethylaminopropylhexahydrotriazine, potassium, potassiumacetate, N,N,N-trimethyl isopropyl amine/formate, and combinationsthereof. A specific example of a suitable trimerization catalyst iscommercially available from Air Products and Chemicals, Inc. under thetrademark POLYCAT®.

Yet further examples of other suitable but non-limiting isocyanatecatalysts include dimethylaminoethanol, dimethylaminoethoxyethanol,triethylamine, N,N,N′,N′-tetramethylethylenediamine,N,N-dimethylaminopropylamine,N,N,N′,N′,N″-pentamethyldipropylenetriamine,tris(dimethylaminopropyl)amine, N,N-dimethylpiperazine,tetramethylimino-bis(propylamine), dimethylbenzylamine, trimethylamine,triethanolamine, N,N-diethylethanolamine, N-methylpyrrolidone,N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylamino-ethyl)ether,N,N-dimethylcyclohexylamine (DMCHA),N,N,N′,N′,N″-pentamethyldiethylenetriamine, 1,2-dimethylimidazole,3-(dimethylamino) propylimidazole, and combinations thereof In variousembodiments, the isocyanate catalyst is commercially available from AirProducts and Chemicals, Inc. under the trademark POLYCAT. The isocyanatecatalyst may include any combination of one or more of theaforementioned catalysts.

In still other embodiments, the catalyst is chosen from DABCO TMR, DABCOTMR-2, DABCO HE, DABCO 8154, PC CAT DBU TA 1, PC CAT Q1, Polycat SA-1,Polycat SA-102, salted forms, and/or combinations thereof.

In other embodiments, the catalyst is chosen from dibutyltin dilaurate,dibutyltin oxide (e.g. as a liquid solution in C8-C10 phthalate),dibutyltin dilaurylmercaptide, dibutyltinbis(2-ethylhexylthioglycolate), dimethyltin dilaurylmercaptide,diomethyltin dineodecanoate, dimethyltin dioleate, dimethyltinbis(2-ethylhexylthioglycoate), dioctyltin dilaurate, dibutyltinbis(2-ethylhexoate), stannous octoate, stannous oleate, dibutyltindimaleate, dioctyltin dimaleate, dibutyitin maleate, dibutyltinmercaptopropionate, dibutyltin bis(isoodyithioglycolate), dibutyltindiacetate, dioctyltin oxide mixture, dioctyltin oxide, dibutyltindiisooctoate, dibutyltin dineodecanoate, dibutyltin carboxylate,dioctyitin carboxylate, and combinations thereof.

The isocyanate catalyst can be utilized in various amounts. For example,in various embodiments, the isocyanate catalyst is utilized in an amountof from 0.0001 to 10, from 0.0001 to 5, from 5 to 10, weight percentbased on a total weight percent of reactants or the isocyanate or anyother value or range of values therebetween. Typically, an amount ofcatalyst used depends on a temperature of the process. For example, at150° F. (about 65.5° C.), 0.0001% may be utilized, while at roomtemperature 0.001 to 10% , such as 5-10%, such as 0.001 to 1%, may beutilized.

The isocyanate-reactive component can also include a “curing agent”,i.e., a crosslinker that crosslinks the carbon-carbon double bonds ofthe polydiene polyol. Examples of curing agents include, but are notlimited to, organic peroxides, sulfur, and organic sulfur-containingcompounds. Non-limiting examples of organic peroxides include dicumylperoxide and t-butylperoxyisopropyl benzene. Non-limiting examples oforganic sulfur-containing compounds include thiuram based vulcanizationpromoters such as tetramethylthiuram disulfide (TMTD), tetraethylthiuramdisulfide (TETD), and dipentamethylenethiuram tetrasulfide (DPTT),4,4′-dithiomorpholine.

The isocyanate-reactive component can also include an adhesion promoter.The adhesion promoter may be a silicon-containing adhesion promoter.Adhesion promoters are also commonly referred to in the art as couplingagents or binder agents. The adhesion promoter facilitates binding thepolyurethane elastomeric coating composition to a subsea structure.

The isocyanate-reactive component can also include a wetting agent. Thewetting agent may be a surfactant. The wetting agent may include anysuitable wetting agent or mixtures of wetting agents known in the art.The wetting agent is employed to increase a surface area contact betweenthe polyurethane elastomeric composition and the subsea structure.

The isocyanate-reactive component may also include various additionaladditives. Suitable additives include, but are not limited to,anti-foaming agents, processing additives, plasticizers, chainterminators, surface-active agents, flame retardants, anti-oxidants,water scavengers, fumed silicas, dyes or pigments, ultraviolet lightstabilizers, fillers, thixotropic agents, silicones, amines, transitionmetals, and combinations thereof. The additive may be included in anyamount as desired by those of skill in the art.

For example, a pigment additive allows the polyurethane elastomericcomposition to be visually evaluated for thickness and integrity and canprovide various marketing advantages.

The hydrolytically resistant layer (20) is not limited to any particulardimensions or thickness. In various embodiments, the hydrolyticallyresistant layer (20) has a thickness of from 0.010 to 12, from 0.010 to6, from 0.010 to 1, from 0.010 to 0.5, from 0.025 to 0.5, from 0.050 to0.5, from 0.025 to 0.1, from 0.025 to 0.05, from 0.05 to 0.1, from 0.05to 0.5, from 1 to 12, from 2 to 11, from 3 to 10, from 4 to 9, from 5 to7, from 5 to 6, from 3 to 6, or from 6 to 12 inches (with 1 inch equalto about 2.54 cm) In various non-limiting embodiments, all values andranges of values between the aforementioned values are hereby expresslycontemplated.

The polyurethane elastomer composition for forming the layer (20) may beprovided in a system including the isocyanate component and theisocyanate-reactive component. The system may be provided in two or morediscrete components, such as the isocyanate component and theisocyanate-reactive (or resin) component, i.e., as a two-component (or2K) system, which is described further below. It is to be appreciatedthat reference to the isocyanate component and the isocyanate-reactivecomponent, as used herein, is merely for purposes of establishing apoint of reference for placement of the individual components of thesystem, and for establishing a parts by weight basis. As such, it shouldnot be construed as limiting the present disclosure to only a 2K system.For example, the individual components of the system can all be keptdistinct from each other.

The hydrolytically resistant layer (20) and corresponding composition isformed from reacting the isocyanate component and theisocyanate-reactive component. Once formed, the hydrolytically resistantlayer (20) and/or polyurethane elastomer composition is chemically andphysically stable over a range of temperatures and does not typicallydecompose or degrade when exposed to higher pressures and temperatures,e.g., pressures and temperatures greater than pressures and temperaturestypically found on the earth's surface. As one example, thehydrolytically resistant polyurethane elastomer composition isparticularly applicable when the composition is used as a layer (20) fora subsea structure (26) and is exposed to cold seawater having atemperature of freezing or above, e.g. about 2 to 5° C., particularlyabout 4° C., and significant pressure and hot oil temperatures of up toabout 150° C., such as about 120 to 150° C., particularly about 130 to140° C. The hydrolytically resistant polyurethane elastomer compositionis generally viscous to solid nature, and depending on molecular weight.

The polyurethane elastomer composition and/or hydrolytically resistantlayer (20) may exhibit excellent non-wettability in the presence ofwater, freshwater or seawater, as measured in accordance with standardcontact angle measurement methods known in the art. The hydrolyticallyresistant layer (20) may have a contact angle of greater than 90° andmay be categorized as hydrophobic. Further, the hydrolytically resistantlayer (20) typically exhibits excellent hydrolytic resistance and willnot lose strength and durability when exposed to water. The polyurethaneelastomer composition can be cured/cross-linked to form thehydrolytically resistant layer (20) prior to disposing the subseastructure (26) into the ocean.

The hydrolytically resistant layer (20) may also exhibit excellentunderwater thermal stability for high temperature and pressureapplications. The hydrolytically resistant layer (20) may be stable attemperatures greater than 100, such as 102° C. The thermal stability ofthe hydrolytically resistant layer (20) is typically determined bythermal gravimetric analysis (TGA).

Method of Forming the Composite Article (10):

This disclosure also provides a method of forming the composite article(10). The method includes the steps of providing the first layer (14),providing the at least one acrylate and the organoborane initiator,providing the epoxide composition, providing the polyurethanecomposition, disposing the at least one acrylate and the organoboraneinitiator on the first layer (14), polymerizing the at least oneacrylate in the presence of the organoborane initiator to form thepoly(meth)acrylate layer (16) that includes a poly(meth)acrylate andthat is disposed on and in direct contact with the first layer (14),disposing the epoxide composition on the poly(meth)acrylate layer (16),curing the epoxide composition to form the epoxide layer (18) thatincludes the epoxide and that is disposed on and in direct contact withthe poly(meth)acrylate layer (16), disposing the hydrolyticallyresistant polyurethane composition on the epoxide layer (18), and curingthe hydrolytically resistant polyurethane elastomer composition to formthe hydrolytically resistant layer (20) that includes the hydrolyticallyresistant polyurethane elastomer and that is disposed on an in directcontact with the epoxide layer (18).

Any one or more of the aforementioned steps of providing may be anyknown in the art. For example, any one or more of the compositions maybe provided or supplied in individual components and/or as combinationsof one or more components. Any one or more of the steps of disposing maybe further defined as applying, spraying, pouring, placing, brushing, orcoating, etc. The components of any one or more of the compositions maybe disposed with, or independently from, any one or more othercomponents. In one embodiment, the step of providing the first layer(14) is further defined as providing the first layer (14) that isalready disposed on a pipe (12). In such an embodiment, the first layer(14) can be used “in-situ” to form the multilayer coating (28) directlyon the pipe (12). Alternatively, the step of providing the first layer(14) may be further defined as providing the first layer (14)independently from the pipe (12). In other words, the first layer (14)may be provided and used independently from the pipe (12). In fact, thepipe (12) is not at all required in the method. The first layer (14) maybe provided and used to form any of the embodiments of the multilayercoating (28) and/or composite article (10).

For example, the hydrolytically resistant polyurethane elastomercomposition for forming the layer (20) may itself be formed by providingthe isocyanate component, providing the isocyanate-reactive componentand reacting the isocyanate component and the isocyanate-reactivecomponent. The method may further include heating the isocyanatecomponent and the isocyanate-reactive component. Alternatively, themethod may include the step of combining the isocyanate component andthe isocyanate-reactive component to form a reaction mixture, andapplying the reaction mixture to form the layer (20). The method mayinclude spraying the reaction mixture.

The isocyanate-reactive component is not required to be formed prior tothe step of applying. For example, the isocyanate component and theisocyanate-reactive component may be combined to form the reactionmixture simultaneous with the step of disposing or applying.Alternatively, the isocyanate component and the isocyanate-reactivecomponent may be combined prior to the step of applying.

The individual components of any of the aforementioned compositions maybe contacted in a spray device. The spray device may include a hose andcontainer compartments. The components may then be sprayed. Thepoly(meth)acrylate and/or epoxide may be fully reacted upon spraying.The components may be separate immediately before they are contacted ata nozzle of the spray device. The components may then be togethersprayed, e.g. onto the subsea structure (26). Spraying typically resultsin a uniform, complete, and defect-free layer. For example, the kayer istypically even and unbroken. The layer also typically has adequatethickness and acceptable integrity. Spraying also typically results in athinner and more consistent layer as compared to other techniques.Spraying permits a continuous manufacturing process. Spray temperatureis typically selected by one known in the art.

Subsea Structure:

The composite article (10) may be further defined as a patch, film,covering, multilayer film or layer, etc, e.g. as shown in FIG. 2. Invarious embodiments, the composite article (10) is used as a patch on/ina subsea structure (26) such as a structure for use during offshore oiland gas exploration endeavors, as shown, e.g. in FIG. 1.

This disclosure provides a subsea structure (26) including a pipe (12)having a length, a first layer (14) disposed on the pipe (12) andincluding the low surface energy polymer, and a multilayer coating (28)disposed on and in direct contact with the first layer (14). The pipe(12) is not limited in composition and may be or include metal,polymers, or combinations thereof. The multilayer coating (28) includesthe poly(meth)acrylate layer (16) disposed on and in direct contact withthe first layer (14), the epoxide layer (18) disposed on and in directcontact with the poly(meth)acrylate layer (16), and the hydrolyticallyresistant layer (20) disposed on and in direct contact with the epoxidelayer (18), wherein the multilayer coating (28) has a peel strength ofat least 50 pli measured between the hydrolytically resistant layer (20)and the epoxide layer (18) using ASTM D6862. In one embodiment, thefirst layer (14) includes a first section and a second section, whereinthe first section is spaced apart from the second section along thelength of the pipe (12) and the multilayer coating (28) is disposedbetween said first and second sections, e.g. as shown in FIG. 2.

Non-limiting examples of suitable subsea structures (26) include pipes(12), flowlines, pipelines, manifolds, pipeline end terminators,pipeline end manifolds, risers, field joints, other joints, jumpers,pipe pigs, bend restrictors, bend stiffeners or christmas trees. Achristmas tree is a type of structure well known in the offshore oil andgas exploration field. It is to be appreciated that other structures notdescribed herein may also be suitable for the purposes of the presentdisclosure. The subsea structure (26) may be a pipe (12) having adiameter of about 12 to about 18 inch diameter (wherein a 12 inchdiameter is about a 30.48 cm diameter and wherein an 18 inch diameter isabout a 45.72 cm diameter). The diameter of a subsea pipe (12) structureis not limited, and may range from a few inches (i.e., a fewcentimeters), in the case of a flowline, to several feet (severalmeters). The length of the pipe (12) is also not limited. In variousembodiments, a multilayer coating (28) is utilized in the subseastructure (26) wherein the multilayer coating (28) is, consists of, orconsists essentially of, the poly(meth)acrylate layer (16), the epoxidelayer (18), and the hydrolytically resistant layer (20). For example,the first layer (14) may be disposed on the pipe (12) and the multilayercoating (28) may be formed using the first layer (14) that is alreadydisposed on the pipe (12). Alternatively, the multilayer coating (28)may be formed using the first layer (14) when the first layer (14) isnot disposed on the pipe (12) such that the multilayer coating (28) maythen be later disposed on the pipe (12).

In various embodiments, the multilayer coating (28) insulates a portionof the subsea structure (26). For example, the multilayer coating (28)may form an exterior partial or full coating having a thickness on thestructure intended for subsea applications. The thickness of themultilayer coating (28) may be half an inch thick (about 1.27 cm thick).Alternatively, the thickness of the multilayer coating (28) may be onefoot thick (about 30.48 cm thick). In one embodiment, the thickness ofthe hydrolytically resistant layer (20) may be about four inches (about10.16 cm). In another embodiment, the thickness of the hydrolyticallyresistant layer (20) may be about six inches (about 15.24 cm). In yetanother embodiment, the thickness of the hydrolytically resistant layer(20) may be about nine inches (about 22.86 cm).

In addition, the multilayer coating (28) may insulate petroleum fuels,such as oil and/or gas, that flows through the subsea structure (26).The multilayer coating (28) may coat a large enough surface area of asubsea structure (26) so that the multilayer coating (28) caneffectively insulate the subsea structure (26) and the petroleum fuels,such as oil, flowing within the subsea structure (26). When thepetroleum fuel, such as oil, is collected from about one to two milesbeneath the ocean floor, the oil is very hot (e.g., around 130° C.).Seawater at this depth is very cold (e.g., around 4° C.). The multilayercoating (28) may insulate the oil during transportation from beneath theocean floor to above the surface of the ocean. The multilayer coating(28) can insulate the oil so that the vast difference in averageseawater temperature and average oil temperature does not substantiallyaffect the integrity of the oil. The multilayer coating (28) typicallymaintains a relatively high temperature of the petroleum fuels such thatthe fuels, such as oil, can easily flow through the subsea structures(26), such as pipes (12) and pipelines. The multilayer coating (28)typically adequately prevents the fuel (oil) from becoming too cold, andtherefore too viscous to flow, due to the temperature of the seawater.The multilayer coating (28) also typically adequately prevents the oilfrom forming waxes that detrimentally act to clog the subsea structures(26) and/or from forming hydrates that detrimentally change the natureof the oil and also act to clog the subsea structures (26). Themultilayer coating (28) may be flexible to enable the subsea structure(26) to be manipulated in different ways. For instance, the subseastructure (26) of this disclosure, such as a pipeline, may be droppedoff the edge of an oil platform, rig or ship, and maneuvered, by machineor otherwise, through the ocean and into the ocean floor. Also, if anyone of the subsea structures (26) is made of an expandable material,such as a metallic material, it may expand due to any one of severalfactors, including heat. The flexibility of the multilayer coating (28)typically allows for the expansion, due to, for instance, heat, withoutbecoming delaminated itself. That is, the multilayer coating (28) canstretch with the expanding subsea structure (26) without deterioratingor delaminating itself. It is to be appreciated that the multilayercoating (28) can also have applications beyond offshore oil and gasexploration, including, but not limited to, any type of underwater,including fresh water and seawater, applications.

Any one or more of the layers may be formed in-situ on the subseastructure (26). The components of any one or more of the layers may becombined at the time of disposing the components onto the subseastructure (26).

EXAMPLE

The example herein compares a polyurethane elastomer formed inaccordance with the present invention to a formulation not formed inaccordance with the present invention for resistance to hydrolysis inhot salt water.

The elastomeric sample plaques were produced using a “book mold,” whichis an aluminum mold that has a top and bottom and which is hinged on oneside and is open on the opposing side. The elastomeric sample plaquescreated for evaluation were approximately 0.3175 cm thick, 25.4 cm wideand 25.4 cm long (i.e., ⅛ inch thick, 10 inches long and 10 incheswide).

For each of the elastomeric plaques the isocyanate-reactive componentswere weighed into a Hauschild Speedmixer cup and then blended using theHauschild Speedmixer (2200 rpm, 30 seconds). Dissolved gasses in thepolyol blend and the isocyanate were removed under vacuum. The requiredamount of isocyanate was then poured into the Speedmixer cup and themixture blended using the Speedmixer for about 40 seconds. The reactionmixture was then poured into an angled, aluminum, oven-heated book moldthat was preheated to 80° C. The plaques (25.4 cm×25.4 cm×0.3175 cm)(i.e., 10 in.×10 in.×⅛ in.) were cured in-mold at 80° C. until curedsufficiently for demolding and then postcured for about 18 hours at 80°C. and then 160° C. for one hour.

Test sample coupons (type S2 tensile bars made according to DIN 53504)were die-cut from the postcured plaques. Initial tensile strength (DIN53504, S2 sample type, crosshead speed, 200 mm/min; Gauge length: 38 mm)was determined after submersing the tensile bars in salt water for atleast 1 month at room temperature. The initial tensile strength was usedto calculate percent loss in tensile strength after exposure. Toevaluate hydrolysis resistance, the tensile bars were submerged in hotsynthetic sea water (ASTM D665) at 102° C. using an autoclave. Thismethod is sometimes referred to as “hot/wet aging.” Specimens wereremoved at predetermined times and tested (without drying) for tensilestrength using the DIN 53504 S2 standard test method.

An example polyurethane formulation in accordance with the presentinvention is shown in Table 1 (formulation quantities are parts byweight). Also shown in Table 1 is Comparison 1, not made according tothe invention. Example 1 contains peroxide and was postcured at 160 Cfor one hour to crosslink the elastomer, according to the presentinvention. Comparison 1 does not contain peroxide (but was alsopostcured at 160 C for one hour).

TABLE 1 Formulations for Example 1 and Comparison 1. Example 1Comparison 1 components parts by weight Polyol 1 55.1 57.0 Polyol 2 33.134.2 Chain Extender 7.3 7.5 Peroxide 3.4 0.0 Drying Agent 1.0 1.0Defoamer 0.3 0.3 Catalyst 0.03 0.03 Isocyanate 38.6 39.9

Raw Materials for Table 1

-   -   Polyol 1—Hydroxyl-terminated poly(butadiene) resin (MW 2800        g/mol, OH#: 47.1, Visc.: 8000 mPa·s (23° C.). Available from        Cray Valley as Poly bd R45HTLO.    -   Polyol 2—Hydrogenated Dimer Diol (OH# 206, MW 537 g/mol).        Available from BASF as Sovermol 908.    -   Chain Extender—2 ethyl-1,3-hexanediol, Sigma-Aldrich.    -   Peroxide—dicumyl peroxide, Sigma-Aldrich.    -   Catalyst—BiCat 8118 from Shepherd Chemical Company (10% in        castor oil).    -   Drying agent—Molsiv 3A, UOP.    -   Defoamer—BYK 066N, Byk Chemie.    -   Isocyanate: Polymeric MDI (PMDI) (% NCO=31.5, f=2.7,        Viscosity=200 mPa·s at 77° F. (25° C.). Available from BASF as        Lupranate M20.    -   Synthetic sea water—ASTM D665 grade, Sigma-Aldrich.

The results of hot/wet immersion testing for the material in Table 1 areshown as plots of the percent change in tensile strength versusimmersion time in FIG. 4. As shown in FIG. 4, Example 1 of the presentinvention lost 13% of its initial tensile strength after 36 weeks ofimmersion in synthetic sea water at 102° C. (after which time testingwas stopped). By contrast, Comparison 1 lost 86% of its initial tensilestrength after 43 weeks of immersion under the same conditions (afterwhich time testing was stopped). For still further comparison, acommercial product used in subsea applications (Elastoshore10060R/10002T; available from BASF Corporation of Florham Park, N.J.)was tested under the same conditions until decomposition (4 weeks) andthe results were also included in FIG. 4.

These results from FIG. 4 clearly show the benefit of the presentinvention for resistance to hydrolysis in hot salt water. Peroxidecrosslinking, as according to the invention, gives the polyurethanematerial the best ability to maintain physical properties (monitored viatensile strength in this example) during long-term immersion in hot saltwater. This accelerated testing gives a good indication thatpolyurethane formulations according to the present invention willmaintain important physical properties for much longer in real-worldsubsea applications in comparison to a non-crosslinked polyurethaneformulation.

It is to be understood that the appended claims are not limited toexpress and particular compounds, compositions, or methods described inthe detailed description, which may vary between particular embodimentswhich fall within the scope of the appended claims. With respect to anyMarkush groups relied upon herein for describing particular features oraspects of various embodiments, it is to be appreciated that different,special, and/or unexpected results may be obtained from each member ofthe respective Markush group independent from all other Markush members.Each member of a Markush group may be relied upon individually and or incombination and provides adequate support for specific embodimentswithin the scope of the appended claims.

It is to be understood that the term average hydroxy functionality isused when referring to a mixture of polymers, such as a mixture of apolyether polyol and a polydiene polyol.

It is also to be understood that any ranges and subranges relied upon indescribing various embodiments of the present disclosure independentlyand collectively fall within the scope of the appended claims, and areunderstood to describe and contemplate all ranges including whole and/orfractional values therein, even if such values are not expressly writtenherein. One of skill in the art readily recognizes that the enumeratedranges and subranges sufficiently describe and enable variousembodiments of the present disclosure, and such ranges and subranges maybe further delineated into relevant halves, thirds, quarters, fifths,and so on. As just one example, a range “of from 0.1 to 0.9” may befurther delineated into a lower third, i.e., from 0.1 to 0.3, a middlethird, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9,which individually and collectively are within the scope of the appendedclaims, and may be relied upon individually and/or collectively andprovide adequate support for specific embodiments within the scope ofthe appended claims. In addition, with respect to the language whichdefines or modifies a range, such as “at least,” “greater than,” “lessthan,” “no more than,” and the like, it is to be understood that suchlanguage includes subranges and/or an upper or lower limit. As anotherexample, a range of “at least 10” inherently includes a subrange of fromat least 10 to 35, a subrange of from at least 10 to 25, a subrange offrom 25 to 35, and so on, and each subrange may be relied uponindividually and/or collectively and provides adequate support forspecific embodiments within the scope of the appended claims. Finally,an individual number within a disclosed range may be relied upon andprovides adequate support for specific embodiments within the scope ofthe appended claims. For example, a range “of from 1 to 9” includesvarious individual integers, such as 3, as well as individual numbersincluding a decimal point (or fraction), such as 4.1, which may berelied upon and provide adequate support for specific embodiments withinthe scope of the appended claims.

The present disclosure has been described in an illustrative manner, andit is to be understood that the terminology which has been used isintended to be in the nature of words of description rather than oflimitation. Obviously, many modifications and variations of the presentdisclosure are possible in light of the above teachings. It is,therefore, to be understood that within the scope of the appendedclaims, the present disclosure may be practiced otherwise than asspecifically described.

1. A composite article comprising: A. a first layer comprising a lowsurface energy polymer; B. a poly(meth)acrylate layer disposed on and indirect contact with said first layer, wherein said poly(meth)acrylatelayer comprises a poly(meth)acrylate comprising the reaction product ofat least one acrylate polymerized in the presence of an organoboraneinitiator; C. an epoxide layer disposed on and in direct contact withsaid poly(meth)acrylate layer, wherein said epoxide layer comprises anepoxide; and D. a hydrolytically resistant layer disposed on and indirect contact with said epoxide layer, wherein said hydrolyticallyresistant layer has an initial tensile strength as measured inaccordance with the DIN 53504 S2 standard test method and comprises ahydrolytically resistant polyurethane elastomer comprising the reactionproduct of: (1) an isocyanate component; and (2) an isocyanate-reactivecomponent comprising a polydiene polyol having an average hydroxyfunctionality of no greater than about 3 and a number average molecularweight of from about 1000 to less than about 2000 g/mol; reacted in thepresence of (3) a curing agent for crosslinking the carbon-carbon doublebonds of the polydiene polyol, wherein said hydrolytically resistantlayer retains at least 80% of said initial tensile strength as measuredin accordance with the DIN 53504 S2 standard test method and aftersubmersion in standardized seawater for 24 weeks at 102° C. inaccordance with ASTM D665.
 2. The composite article of claim 1 whereinsaid poly(meth)acrylate is covalently bonded to said low surface energypolymer.
 3. The composite article of claim 1 wherein said low surfaceenergy polymer is selected from polypropylene, polyethylene, andcombinations thereof.
 4. The composite article of claims 1 wherein saidpoly(meth)acrylate is a self-polymerization product of a C1-C20 alkylacrylate or methacrylate.
 5. The composite article of claim 1 whereinsaid poly(meth)acrylate is a reaction product of a first C1-C20 alkylacrylate or methacrylate and a second C1-C20 alkyl acrylate ormethacrylate.
 6. The composite article of claim 1 wherein saidpoly(meth)acrylate is a reaction product of a first C1-C20 alkylacrylate or methacrylate, a second C1-C20 alkyl acrylate ormethacrylate, and a third C1-C20 alkyl acrylate or methacrylate.
 7. Thecomposite article of claim 1 wherein said epoxide is the reactionproduct of an epoxy compound and an amine.
 8. The composite article ofclaim 1 wherein said organoborane initiator is further defined as anorganoborane-organonitrogen complex.
 9. (canceled)
 10. The compositearticle of claim 1 wherein said organoborane initiator is anorganoborane-amine complex and said at least one acrylate is polymerizedin the presence of said organoborane-amine complex and an amine-reactivecompound.
 11. (canceled)
 12. The composite article of claim 1 whereinsaid composite article has a peel strength of at least 50 ph measuredbetween said hydrolytically resistant layer and said epoxide layer usingASTM D6862.
 13. (canceled)
 14. The composite article of claim 1 whereinsaid hydrolytically resistant layer retains at least 99% of said initialtensile strength as measured in accordance with the DIN 53504 S2standard test method and after submersion in standardized seawater for24 weeks at 102° C. in accordance with ASTM D665.
 15. (canceled)
 16. Amethod of forming the composite article claim 1, said method comprisingthe steps of providing the first layer of the low surface energypolymer; providing the at least one acrylate and the organoboraneinitiator; providing the epoxide; providing the isocyanate component andthe isocyanate-reactive component; disposing the at least one acrylateand the organoborane initiator on the first layer; polymerizing the atleast one acrylate in the presence of the organoborane initiator to formthe poly(meth)acrylate layer; disposing the epoxide on thepoly(meth)acrylate layer, curing the epoxide to form the epoxide layer;disposing the isocyanate component and the isocyanate-reactive componenton the epoxide layer; and reacting the isocyanate component with theisocyanate-reactive component in the presence of the curing agent forcrosslinking the carbon-carbon double bonds of the polydiene polyol toform the hydrolytically resistant layer and the multilayer coating. 17.A subsea structure comprising: A. a pipe having a length; B. a firstlayer disposed on said pipe and comprising a low surface energy polymer;C. a multilayer coating disposed on and in direct contact with saidfirst layer, wherein said multilayer coating comprises: (1) apoly(meth)acrylate layer disposed on and in direct contact with saidfirst layer, wherein said poly(meth)acrylate layer comprises apoly(meth)acrylate comprising the reaction product of at least oneacrylate polymerized in the presence of an organoborane initiator; (2)an epoxide layer disposed on and in direct contact with saidpoly(meth)acrylate layer, wherein said epoxide layer comprises anepoxide; and (3) a hydrolytically resistant layer disposed on and indirect contact with said epoxide layer, wherein said hydrolyticallyresistant layer has an initial tensile strength as measured inaccordance with the DIN 53504 S2 standard test method and comprises ahydrolytically resistant polyurethane elastomer comprising the reactionproduct of: (a) an isocyanate component; and (b) an isocyanate-reactivecomponent comprising a polydiene polyol having an average hydroxyfunctionality of no greater than about 3 and a number average molecularweight of from about 1000 to less than about 2000 g/mol; wherein saidhydrolytically resistant layer retains at least 80% of said initialtensile strength as measured in accordance with the DIN 53504 S2standard test method and after submersion in standardized seawater for24 weeks at 102° C. in accordance with ASTM D665.
 18. The subseastructure of claim 13 wherein the subsea structure has a peel strengthof at least 50 pli measured between said hydrolytically resistant layerand said epoxide layer using ASTM D6862.
 19. (canceled)
 20. The subseastructure of claim 13 wherein said hydrolytically resistant layerretains at least 99% of said initial tensile strength as measured inaccordance with the DIN 53504 S2 standard test method and aftersubmersion in standardized seawater for 24 weeks in accordance with ASTMD665.
 21. (canceled)
 22. (canceled)
 23. (canceled)
 24. (canceled)